Honda CB750 CB900 CB900C CB900F CB1000 CB1100F CB1100R Sprag type Starter Clutch

Description

The starter clutches that I rebuild use a Yamaha R6 Sprag type clutch. Most modern motorcycles use a sprag type starter clutch since the sprag can take a higher torque, provides longer life and results in less noise than the stock 3 roller unit. It uses 20 sprags or dogs that lock the crank shaft gear to the starter gears when turned in one direction and freewheels when turned in the opposite direction. This allows the starter to lock up solid when starting the engine, and then releases when the engine starts.
The key to making a long lasting unit is to surface grind each gear so it meets the sprag manufacturer's specification for diameter and surface finish. The worn surface of the used gear race and the out of spec diameter could lead to premature failure. The stock starter gear is too large for the sprag and if it were used as-is then it is nearly impossible to get the sprag onto the gear race without disassembling the unit.
Six holes are precision drilled and reamed in the starter flange to ensure that the sprag is mounted precisely on center. The flange is also test fit onto both 750/900 and 1100 crankshafts to ensure that the splines are not damaged. If the unit does not slide on easily then the splines are de-burred and polished. This ensures that you won't have to take a hammer to it during the install.
The unit is then masked and bead blasted to remove any corrosion or crud from the previous engine. It is then assembled using a precision torque wrench and red Loctite so it is bolt-on ready when you receive it.  Here are some comments and feedback that I have received.
"Dropped the starter clutch back on, attached the outer case and reconnected the battery and away we went. Perfect upgrade, thanks very much. No more slipping starter clutch, so the bike fires up a treat. I would recommend this to all CBF owners"
"Hi, just to let you know its a perfect fit on my cb1100r so add that to your list of applications"
"I just replaced the starter clutch with one of these and WOW!!....I have never heard an F bike start like this, ever. If you haven't done this yet, you must. Incredible "
"The starter drives arrived yesterday, installed the parts last night. I can tell you that they are top notch, first class pieces."